What is the difference between gamma rays and beta rays?

Beta particles are composed of electrons or their antiparticles, positrons. Beta particles are high-energy electrons. They are not electrons from the electron shells around the nucleus, but are generated when a neutron in the nucleus splits to form a proton and an accompanying electron. Beta particles are negatively charged.

Gamma particles are very high frequency photons (the same particles that make radio waves, light, and X-rays, but with a higher frequency and therefore energy). They can penetrate the farthest. Gamma rays have no electrical charge associated with them.